The invention relates generally to impedance plethysmography and more specifically to electronic means for monitoring changes in a plurality of separate skin segments of a human responsive to peripheral blood flow adjacent thereto.
Prior art methods of monitoring skin segments response to blood flow include multiple frequency impedance systems that require balancing of each impedance bridge frequencies manually prior to the taking of measurements. This system had restricted use due to the fact that they were very sensitive and required a laboratory environment for reasonable operation. Also, the maximum number of channels available are limited due to potential harmonic distortions between the impedance systems.
Other state of the art impedance measurement systems provided for self balancing frequency bridge circuits providing for use in other than laboratory environments, however, these systems are limited to single channel operation.
These and other means impedance measuring systems fail to provide for simultaneous monitoring of a plurality of separate skin areas within a skin segment.
This and other monitoring limitations have not been resolved until the emergence of the instant invention.